Question

The potential energy diagram for a reaction $X$ $\rightarrow$ $Y$ is given. $A$ and $C$ in the graph corresponding to

• A. $A$ $\rightarrow$ activation energy, $C$ $\rightarrow$ $\Delta H^{^{\circ}}$
• B. $A$ $\rightarrow$ energy of reactants, $C$ $\rightarrow$ energy of products
• C. $A$ $\rightarrow$ $\Delta H^{^{\circ}}$, $C$ $\rightarrow$ activation energy
• D. $A$ $\rightarrow$ activation energy, $C$ $\rightarrow$ threshold energy

Answer 1

Answer: (A)

Activation energy is defined as the least possible amount of energy (minimum) which is required to start a reaction or the amount of energy available in a chemical system for a reaction to take place $\rightarrow$ A.
$C \rightarrow \Delta H ^{\circ}$ is the difference of the forward and backward activation energies.